Barometric altimetry is the standard by which air traffic maintains vertical separation. Above a transition altitude, each aircraft is required to maintain a standard altimeter setting to ensure adequate separation. Below a transition level, each aircraft is required to maintain a local setting in the altimeter to 1) maintain separation from other aircraft, and 2) accurately maintain clearance above surface obstacles.
Traditional barometric altimetry requires pilot action in this transition between the standard setting (e.g., 29.92 inches mercury (inHg)) and the local setting (e.g. QNH, QNE). The pilot must reach to the instrument panel and physically twist a knob to the desired setting. Passing this transition, the pilot must set the proper setting in the altimeter (climbing set to standard 29.92, descending set to local). This pilot action must be timely at the transition altitude and transition level since a level off at an altitude just after passing the transition may be required. In some cockpits, a Z axis of a knob (a push of the knob) may set the altimeter to a standard setting of 29.92.
Traditional barometric systems may utilize 1) air data system, 2) flight displays, and 3) a barometric altimeter adjustment knob with manual pilot action to set the desired barometric pressure.
Transition altitudes and transition levels vary throughout the world. For example, in the US, transition altitude (climbing) is 18,000 feet Mean Sea Level (MSL) while the transition level (descending) is Flight Level (FL) 180. In the Netherlands, however, transition altitude is 3,000 ft. MSL while transition level is FL40. Operating in Beijing, China, the transition level is FL118 while the transition altitude is 9850 ft. MSL.
Without experience in these theaters of operation, a pilot may be unfamiliar with current altimetry requirements. Single piloted aircraft require continuous attention to detail where altimetry may fall out of the scan pattern of a task saturated pilot. An error in altimetry setting may possibly reduce a desired margin of safety.
Upgraded avionics displays may require/demand less mechanical input. A display system designed for pilots in a flight deck requiring a mechanical pilot input may be less economical. In addition, a mechanical device may be prone to failure since miniature gears and dials may fail over time.
Although traditional federated systems may share information, they may lack an ability to fully integrate a device and may not allow two-way communications between the integrated device and the system as a whole.
Therefore, a need remains for a system and related method to automate the setting of the barometric altimeter, so that human error and mechanical requirements are minimized. Further, a system and related method to automate the setting of the barometric altimeter to allow a reduction in pilot workload an increase in safety, and an elimination of a dedicated flight deck knob is desired.